Telephone system



l TELEPHONE SYSTEM Filed Dec. 20, 1930 2 Sheets-Sheet 1 FIG. 2

INVENTOR CHARLES. E. HARTLEY April 18, 1933- c. B. BARTLEY TELEPHONE SYSTEM Filed Dec. 20, 1930 2 Sheets-Sheet 2 FIG. 7

J Y W. E m mu m m m W8 W8. w jw J 5 m A MW Patented Apr. 18, -l933 UNITED STATES PATENT, orator.-

cmnn's a. mum, or rrrrsnunem rmmsnvnnmy Assre ron T0 wns'rnmw IELECTRIG COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF Application. filed December so, 3930. Serial No. 503,703.

This invention relates to telephone signal ing systems and particularly to such systems wherein alternating current is employed to effect the actuation of a signaling device at a called subscribers station.

Heretofore, in signaling a called subscriber it has beencommon practice to employ This practice in most cases has proven satisfactory, particularly where a subscriber has but one telephone to attendto, and also where a plurality of telephones are locate'd in the same locality'but sufliciently remoyed from one another to preclude thepossibility of confusion as to which telephone was signaled. However, there are numerous occasions, such as in brokerage houses, department stores and the like, where an operator 'or an attendant is called upon to handle incoming calls on- -a plurality 'of closel associated telephones.

Invariably, these te ephones are so closely grouped together that, unless'the attendants sense of hearing is so unusually keen as to permit him to readily discriminate between various tone signals, he would be-unable;to determine which telephone. was bemgfsignaled.

e It is accordingly the object of this invention to enable an attendant to quickly and conveniently detect which one'of aplurality of closely grouped telephones is being signaled.. This object is attamedm accordance with a feature of the invention by the provision of a visual signaling ,device' individually as-. sociatedwith each of the telephones in' a group and responsive to the regular signal.

. mg current usually employed in actuating the erators cord circuit which in establishingtelephonicconnection with the substation, and; shows one method of connecting well-known audible ringer.-

I I in? in. which,

g. 1 is a; circuit diagram of a simple sub station line circuit and a portion of an opmaybe employed the visual signal to the line; Fig. -2 is a modification of the substation e invention will be readily understood from the following detailed description made with reference to the accompanying draw-- lamp 18 circuit arrangement shown in Fig. 1- and Figs. 3,and 4 are substation circuit dis-" closures showing other methods of connect- 1 .ing the visual signal to the substation circuit; an audible signal at the subscribers station.

Fig. 5 is a perspective .view showing how the visual si nalmay be mounted on a cradle typedesksetp f j q Fig. 6 shows the method (if-mounting the visual signal on the ordinary'upright type ofdeskset;and p v Fig. 7 is a perspective view showing a portion of a room or ofiice inwhich'a plurality of telephones are closely grouped, a condition which renders this invention particular-Q ly desirable.

' In eachof the figures disclosed in'the draw Y ings, a glow discharge tube, in the form of a neon lamp, is'utilized as the visual signal ataudible type'ringen' at energy levels terminates in a plug 13 at an operators position at which the jack 11 is located. In signallng the substation, the operator 1 inserts key 14. Av circuit is thereupon established from the AG signaling source 15, lower contacts of ringing key 14; ring contacts of plu 13 and jack 11, ring cohductor 16 of the sub -scribers line 10 through the ringer circuit includingringer 17,- and condenser 25, and glow lamp 18 in parallel, conductor 19'of the line 10, tip contacts of jack 11 and plug.

13to ground by way of the \upper contacts of ringing key 145' The ringer-17 and glow are energized this circuit, the

operating the usual esa'nd are readily adaptable for operaa Referring to Fig. the subscribers line Y M 10 is shown terminating at .a central oflicew in a jack 11. 'An operators cord circuit 12 $5- plug 13 intojack'll and actuatesthe ringing l iaiiy former giving the usual-audible signal and the latter a distinctive visual signal. It is evident that, irrespective of how many telephones are grouped together within a small area, there will be no uncertainty as to which of the telephones is being signaled when the regular audible signal is accompanied by a visual identification. I

When the attendant at the signaled telephone removes the receiver 20 in answer to the incoming call the signaling equipment at the substation is short-circuited at the receiver switchhook contacts.

It is obvious from the foregoing description that the glowlamp 18 will be lighted only while the signaling current is on the line, prior to the removal of the receiver at the called station.

'In' some cases, particularly where the sub- 20 scribers station is located at a relatively great distance from the central oflice, it is found desirable to employ a step-up transformer in orderto bring the voltage of the signaling source u to a value equal to, or greater than,- the brea down voltage of the glow lamp.

Fig. 2 shows a circuit arrangement suitable for such a contingency. The primary wind-I step-up transformer is bridged 7 across the conductors of theline' 10 at the ing 22 of the contacts of the receiver switchhook,'while the glow lamp 18 is connected in series with the secondary coil 23. The condenser 24 is connected in circuit with theprimary coil 22 in order to prevent the passage of direct currentwhen the talking-circuit is established. It is believed unnecessary to enter into a detailed description of the operation of the circuit shown in Fig.2, as that already 'ven in connection with Fig.1 is sufiiciently applicable.

ig. 3 shows the glow lamp bridgedacross the condenser 25 in the ringing circuit, whereas Fig. 4 shows it connected in shunt with the ringer-17 itself. These alternative arrangements istics oithe ringer circuit and particularly to the capacity of the ringing condenser 25.

From the fore 0mg description, it is apparent that applicant has devised a simple, economical and very practical signaling arrangement wherein the usual audible signalis accompanied by a visual indication and wherein the visual signal is actuated directly current from the signaling source and not through the instrumentality of an auxilringmg relay; the practica application of applicants invention to standar telephones any desirable method of securing the lamp to the telephone, whether it be a desk set, hand set or wall set ma be employed. Figs. 5 and 6 illustrate simple clamping arrangements suitable for desk sets of the cradle and upright types of telephores.

for connecting the glow lamp in circuit depend upon the electrical character of closely grouped-- te Referring to Fig. 5 a bracket 30 isshown secured to a cradle type telephone by means of a clamp 31. The signaling device is mounted on the outwardly extending end 32 of bracket 30 by means of a screw 33 which passes through the bracket end 32 and engages the lower end of the signaling device casmg 34. Within the casing the 'transformer,'comprising windings 22 and 23 herein-.

before referred to, and condenser 24' may be mounted in any suitable manner. The lamp 18 is screwed into the upper end of the casing 34. An aperture 35 is located near the neck;

of the cradle to permit the wires 36, which connect the signaling device with the telephoneline, to be passed through.

In Fig. 6 a uhaped clamp 37 havi g bi- -furcated ends is employed to mount the signaling device to the usual upright type of telephone.

InfFig. grouped desks 40, 41 and 42 each of which is -7 there are shown. three closely provided with a telephone, the desk 40 havingtwoJ It 1s evident that, without applicants visual signal 18, there would be con-v fusion as to which of'the several telephones was being signaled by theiusual audible ring 1 er. Such confusion would be greater inthe case of the attendantlocated at desk 40; The association of a visual signal witheaeh telephone, actuated simultaneously with the audible ringer, precludes the possibility of any such confusion and enables an attendant to immediately select the signaled telephone regardless of his position in the room;

' WhatI claim is: v

1. A. telephone substation including a signal lamp associated. with the instruments comprising said substation and arranged in the circuitnetwork of'said substation to reids spond directly and only to incoming signaling current. V

2. A telephone substation including a glow discharge lamp associated with the instruments comprising said substation and arranged inthe circuit network of said substation to respond directly and only to incomin signaling current. I

v 3. In a telephone system, a plurality of lines each terminatin in one of a plurality,

fephone substation sets, an audible signal for each said set and a lamp ill;

signal for visually indicating the set being .signaled associated with each said set and responsive directly and only to incoming signaling current .for actuating said audible signal.

4. In a telephone system, a plurality of lines each terminating-in one of a plurality of closely grouped telephone substation sets, a

an audible signal for each said set and a neon lamp signal for visually indicating the set being signaled associated with each said set responsive directly and only to incoming signaling current for actuating said audible signal.

5. In a telephone system, a plurality of telephone lines each terminating in one of a plurality of closely grouped telephone substation sets, and an attachment for each of said telephones including a lamp signal for visually indicating the signaled telephone responsive directly and only to signaling' current incoming over said lines, said visual signal being bridged across a pair of switchho'ok contacts at its respective telephone set and adapted to be short-circuited by the removal of the receiver thereat.,

6. In a telephone signalling system, the combination of an alternating current ringing circuit, visual and audible signalling devices included in multiple in said circuit, and condenser means also included in said circuit in series with said signalling devices.

7. In. a telephone signalling system, the

combination of a ringing circuit including in series an audible signalling device and a condenser, a circuit shunting the audible signalling device and a'visual signalling device included in the shunt circuit.

- 8. A. telephone signalling circuit comprising a ringing circuit including asuitablesource of alternating current supply, andmeans for closing said circuit, a visual signalling circuit shunted across the ringing circuit, and a visual signal included in said shunt circuit, whereby the visual signal is adapted to be energized by current from the ringing circuit. a

9. A telephone signalling circuit compris= ing a ringing circuit including a suitable source of alternating current supply, and

current through a visual signalling device and precluding the flow of direct current through the visual signalling device by causing the diverted portion of the ringing cur: rent to pass through a'condenser.

.13. In a telephone signalling system, the combination of a ringin circuit including in series an audible signalling device and a condenser, a circuit shunting the condenser and a visual signalling device included in the shunt circuit.

In testimon whereof, I si my name. HARLES B. ARTLEY.

means for closing said circuit, a visual signalling circuit shunted across the ringing circuit, and a non-filament tube included in said shunt circuit, whereby the non-filament tube is adapted to be energized by current from the ringin circuit.

10. In a telephone signalling system, the combination of an alternating current signalling circuit including in multiple an audi-, ble signalling device and a non-filament tube, and condenser means in series with both the audible signalling device and the non-fila= I ment tube. 7 11. The herein described method of sig- 

